1. Field of the Invention
The present invention relates to a collapsible rack for transport and storage of flat or semi flat objects.
2. Description of Related Prior Art
Racks for keeping flat objects organized and protected during transport and storage is a well known item. These racks are known from a number of different technical fields. We may here mention electronic industry where printed circuit boards with components installed often are stored and transported this way, both during assembly in so called surface mounting lines and for delivery of fully assembled and semi-assembled boards. Racks are also used during curing and similar treatment of the printed circuit board prior to installation of components. One such rack is known from U.S. Pat. No. 4,761,044 showing a rack which have an adjustable width. This will make it possible to adjust the rack for the specific printed circuit board currently in use. Another rack is known from U.S. Pat. No. 5,593,046. This rack is foldable but have a great number of hinges which will make it very difficult to ensure parallelity between the panels carrying the printed circuit boards. It will furthermore be very difficult to ensure that the panels and the arms connecting them relate to one another perpendicular as seen from above. The design is also rather complicated and therefore costly. Since each arm is provided with no less than three hinges, it will become impracticable to obtain any acceptable tolerance.
It is also known to use racks in food industry as for example in bakeries and for trays in restaurants.
In very many cases these racks will have to be transported without carrying any content. It is therefore be beneficial if it was possible to reduce the size of such an empty rack in some way in order to minimize the transport cost. It is of course possible to disassemble a rack and to assemble it again after transport. However, this would require special skill and training of the personnel as well as an increased wear and tear of the different parts would occur. There is also a risk of loosing parts and tolerances in an assembled rack would inevitably be hampered. It is in many cases important to uphold narrow tolerances as well as stability since especially electronic components can be rather valuable as well as sensitive.